Sheep Dung Composition and Phosphorus and Potassium Release Affected by Grazing Intensity and Pasture Development Stage in an Integrated Crop-Livestock System
Fernando Arnuti,
Luiz Gustavo de O. Denardin,
Pedro Arthur de A. Nunes,
Lucas A. Alves,
Diego Cecagno,
Júlia de Assis,
Walker da S. Schaidhauer,
Ibanor Anghinoni,
Abad Chabbi,
Paulo César de F. Carvalho
Affiliations
Fernando Arnuti
Departament of Soil Science, Federal University of Rio Grande do Sul, 7712 Bento Gonçalves Avenue, Porto Alegre 91540-000, RS, Brazil
Luiz Gustavo de O. Denardin
Departament of Soil Science, Federal University of Rio Grande do Sul, 7712 Bento Gonçalves Avenue, Porto Alegre 91540-000, RS, Brazil
Pedro Arthur de A. Nunes
Department of Forage Plants and Agrometeorology, Federal University of Rio Grande do Sul, 7712 Bento Gonçalves Avenue, Porto Alegre 91540-000, RS, Brazil
Lucas A. Alves
Departament of Soil Science, Federal University of Rio Grande do Sul, 7712 Bento Gonçalves Avenue, Porto Alegre 91540-000, RS, Brazil
Diego Cecagno
Departament of Soil Science, Federal University of Rio Grande do Sul, 7712 Bento Gonçalves Avenue, Porto Alegre 91540-000, RS, Brazil
Júlia de Assis
Departament of Soil Science, Federal University of Rio Grande do Sul, 7712 Bento Gonçalves Avenue, Porto Alegre 91540-000, RS, Brazil
Walker da S. Schaidhauer
Departament of Soil Science, Federal University of Rio Grande do Sul, 7712 Bento Gonçalves Avenue, Porto Alegre 91540-000, RS, Brazil
Ibanor Anghinoni
Departament of Soil Science, Federal University of Rio Grande do Sul, 7712 Bento Gonçalves Avenue, Porto Alegre 91540-000, RS, Brazil
Abad Chabbi
French National Research Institute for Agriculture, Food and Environment (INRAE), Poitou-Charentes, 86600 URP3F Lusignan, France
Paulo César de F. Carvalho
Department of Forage Plants and Agrometeorology, Federal University of Rio Grande do Sul, 7712 Bento Gonçalves Avenue, Porto Alegre 91540-000, RS, Brazil
Animal grazing in integrated crop-livestock systems (ICLS) results in continuous nutrient release to forage plants and crops in succession. This study aimed to assess sheep dung composition and decomposition rates under distinct grazing intensities and at different development stages of Italian ryegrass pasture (Lolium multiflorum Lam.), and to evaluate dung phosphorus (P) and potassium (K) release dynamics during two annual ICLS cycles (2015 and 2016) in southern Brazil. Treatments consisted of two grazing intensities (moderate and light) and two pasture development stages (vegetative and post-flowering), arranged in a randomized complete block design with split-split-plots and four replicates. Dry matter (DM) decomposition and P and K release rates were determined using litter bags with sheep dung. Grazing intensity did not affect sheep dung composition. Forage consumed at different development stages altered sheep dung composition, decomposition, and P and K release rates. Dung sampled at pasture vegetative stage showed P and K contents 16% and 7% higher, respectively, than dung from the post-flowering stage. Dung collected at pasture post-flowering stage had 26% more cellulose and 34% more hemicellulose compared to dung from the vegetative stage in 2016. P and K release was greater for dung from pasture vegetative stage, reaching 3.7 and 12.9 kg ha−1 of P and K, respectively. Further evaluations are still needed considering the quantification and release of nutrients in each of the different compartments (pasture, urine, and dung residues) that compose the system.
